Treatment of tall oil fatty acids

Abstract

A process is disclosed for treating tall oil fatty acids with a zinc catalyst and an iodine catalyst to improve the color and color stability of distilled products. The zinc catalyst is employed in an amount of from 0.01% to about 2.0% by weight of fatty acid and the iodine in an amount from 50 to 500 parts per million of fatty acid. The tall oil fatty acids are treated with the iodine and zinc catalysts at a temperature between 150° C. to 275° C.

What is claimed is: 
     
       1. A process for upgrading the color and maintaining the color stability of tall oil fatty acids without changing the physical character of the fatty acids, which comprises; (a) treating said fatty acids with from 50 to 200 parts per million iodine and elemental zinc metal in an amount from 0.01% to about 2.0% by weight of said fatty acids at a temperature from about 150° C. to 275° C.; and   (b) distilling the thus treated fatty acids and obtaining tall oil fatty acids having improved color and color stability.   
     
     
       2. The process according to claim 1 wherein said iodine is present in an amount from 100 to 200 parts per million and said zinc is present in an amount from 0.05% to 0.5%. 
     
     
       3. The process according to claim 1 wherein the time for treating with iodine and zinc together is at least 5 minutes. 
     
     
       4. The process according to claim 1 wherein the iodine treatment precedes the zinc treatment. 
     
     
       5. The process according to claim 1 wherein the iodine treatment and zinc treatment are carried out co-currently. 
     
     
       6. The process according to claim 1 wherein the zinc treatment precedes the iodine treatment. 
     
     
       7. The process according to claim 1 wherein both the iodine and zinc treatments are at a temperature of from about 175° C. to 235° C.